When I heard that daredevil Nik Wallenda will attempt to be the first person to cross over the Grand Canyon on a tightrope, I thought "That's crazy." Not because it's 1,500 feet up and a quarter-mile across with no harness or net, but because the National Park Service allowed it.

Here's the thing, though: it didn't.

Rather, Wallenda's death-defying deed will take place today east of the park, across the gorge of Little Colorado River Navajo Tribal Park. It's on land of the Navajo Nation, near Cameron, Arizona.

"The event would not have been approved in Grand Canyon National Park," says Maureen Oltrogge, the park’s public affairs officer. Under National Park Service regulations, she says, "events must not unreasonably impair the park's atmosphere of peace and tranquility or have an unacceptable impact on the experience of park visitors."

Little Colorado Gorge (Photo credit: GOC53)

That doesn't make the stunt any less risky or the visuals any less spectacular. Wallenda's two-inch (5 cm) cable spans 1,400 feet (426 m) across the gorge, 1,500 feet (457 m) above ground; that's higher than the State Building. Plus, the site is likely to be buffeted with winds up to 30 mph (48 kph).

Although the tribal park is not in the actual Grand Canyon, they're close neighbors. Some have called it a "little Grand Canyon," and the Little Colorado River feeds into the Colorado River in the Grand Canyon.

Permitting Wallenda's walk was not a casual decision, says Geri Hongeva, spokesperson for Navajo Parks & Recreation. "Discovery Channel, NBC Peacock Productions and Nik Wallenda all had to complete a number of clearances and gain proper permits," including archaeological, biological and environmental surveys, and handle tribal park land use fees and filming approvals. Extreme sports are permitted only rarely on tribal lands.

To protect the environment and the gorge's cultural significance, Hongeva says, "There will be no public access to the skywire event site, but we will host a community event a mile from the Skywalk area, where the public can watch on a Jumbotron screen with some local entertainment."

The payoff? "Realistically, the Navajo Nation would not be able to afford this amount of marketing on its own," Hongeva says. "Many people will learn more about the Navajo people and culture." She also expects increased tourism to the area; new road has been built to the site of Wallenda's walk.

The Discovery Channel will air the broadcast at 8pm EDT Sunday, June 23, live (well, with a 10-second delay, for reasons you might imagine).

As for that no harness or net thing, Wallenda says, "I've trained for holding on to that cable if there is an emergency." Rescue teams will be stationed on both sides of the canyon, and helicopters can be there to rescue him within 60 seconds.